The prosecution gave its closing arguments in the Oscar Pistorius trial on Thursday in Pretoria, South Africa. Lawyer Gerrie Nel did his best to prove that the Olympian intentionally shot and killed girlfriend Reeva Steenkamp on Valentine’s Day of last year. The defense has argued that Pistorius fired four rounds through his bathroom door, thinking an intruder had entered his home.

Nel’s final statements focused on the inconsistencies of Pistorius testimony. The double-amputee was untruthful about running to the balcony to call for help, as photos showed that a large fan would have blocked him from doing so. Mistakes in Pistorius’s comments about his alarm system also led Nel to call into question the defendant’s account of the night.

Pistorius was called an “appalling witness,” for lying in court. Nel pressed Pistorius as he testified on the stand in the early part of the trial, and refused to believe the defendant’s claims.

"We cannot argue that he was the worst witness ever, that honor belongs to someone else," said the prosecution's written argument, via the Associated Press. "The accused was, however, demonstrably one of the worst witnesses ever encountered."

The defense of Pistorius was also called into question. While the 27-year-old has contended that he shot what he thought was an intruder, his lawyers also have suggested that Pistorius was startled and accidentally fired his weapon.

According to the prosecution, the shooting was prompted by an argument between the couple. Nel attempted to prove that Steenkamp was afraid of Pistorius, highlighting certain text messages between the two. Witnesses for the prosecution have testified that they heard a woman and a man screaming before hearing gunshots.

Closing arguments will conclude on Friday with defense attorney Barry Roux’s final statements. Judge Thokozile Matilda Masipa could take several weeks to make her final decision. The trial began in March and has featured multiple delays, most notably because of the Easter holiday and a month-long mental health evaluation of Pistorius.